Gas-turbine



A. UNDERDAHL.

GAS TURBINE.

APPLICATION HLED JAN.5, 1918.

1,342,314. Patented June 1,1920.

4 SHEETS-SHEET I.

A. UNDERDAHL'.

GAS TURBINE.

APPLICATION FILED 1AN.5.1918.

Patented J 11110 1, 1920-.

4 SHEETS-SHEET 2.

Allzzderd w A. UNDERDA-HL GAS TURBINE- APPLICATION FILED m5. 1-91.23.

1,342,314, Patented June 1, 1920.

4 SHEETSSHEET 3.

VIIIIIIA "III/III 'A. UNDERDAHL.

GAS TURBINE.-

APPLICATION HLED mm. 1918.

Patented June 1, 1920.

4 SHEETSQSHEET 4.

UNITED STATES PATENT OFFICE.

ALBERT UNDERDAHL, OF CANNON FALLS, MINNESOTA.

GAS-TURBINE.

Application filed January 5, 1918. Serial No. 210,480.

To all whom it may concern:

Be it known that'I, ALBERT UNDERDAHL, a citizen of the United States,residing at Cannon Falls, in the county of Goodhue and State ofMinnesota, have invented certain new and useful Improvements inGas-Turbines; and I do hereby declare the following to be a full, clear,and exact description of the invention, such as will enable othersskilled in the art to which it appertains to make and use the same.

This invention relatesto rotary engines of the internal combustion typeand has for its object to provide an engine including a novel type ofvalve controlled combustion chamber from which the expanded gasessubsequent to ignition are liberated and directed against the blades ofa rotor. v

Another object is the provision of means for locking the valve in thecombustion chamber in open position for a predetermined period.subsequent to combustion so as to secure the maximum effect of the expanded gases upon the blades of the rotor.

Another object is the provision of an improved compressor for deliveringthe gaseous fuel to the combustion chamber under pressure. WVith theseand other objects in view, the invention consists. in the novelconstruction, combination and arrangement of parts as will behereinafter specifically described, claimed and illustrated intheaccompanying drawing, in which:

.Figure 1 represents a longitudinalj sectional view through the turbine,

Fig. 2 represents an enlarged verticalsectional view through one of therotor housings and combustion chambers,

Fig. 3 represents a detail sectional view on the line 3-3 of Fig. 2,

Fig. 4 represents an enlarged sectional view through the throttle valvegovernor,

Fig. 5 represents an end elevation of the turbine partly in section,

Fig. 6 represents a detail sectional view through the throttle valve,and 1 Fig. 7 is a perspective of the turbine.

Referring to the drawings in detail, wherein similar" reference numeralsdesignate corresponding parts throughout the several views, the numeral5 indicates generally the casing of the engine, which is dividedcentrally by a vertical partition 6 intorotor and gear housings 7 and 8,re-

, spectively. The rotor shaft 9 is journaled in bearings 10 provided inthe end wall of the rotor housing 7 and the partition 6 and the end ofthe rotor shaft, which projects within the chamber of the gear housing8, is provided with pinions 11, which mesh'with gear wheels 12 securedupon the driven shaft 13. The shaft 13 is journaled in bearings 14provided in the partition 6 and end wallof the gear housing 8 and alsoin an intermediate bearing support 15 arranged upon the bottom of thegear housing 8.

The rotor housing 7 is preferably provided with a circumferentialchamber 16 for the reception of water to assist in cooling the engineduring operation and the inner surface of the cylindrical wallof thehousing is provided with a plurality of internal annular grooves 17receiving the rims of the several rotors 18, which are secured to andsupported upon the rotor shaft 9.

A hollow cylinder 19 is, formed on the top of'the rotor housing 7adjacent each internal groove 17 and communicates therewith by arestrictedinlet port 20, which is disposed at an angle to a radial planethrough the rotor housing so as to direct the expanded gases against theblades21 of the rotor so as to revolve the latter. The cylinders 19 arearranged in a horizontal position and are provided intermediate theirends with internally threaded openings 22 to receive preferred types ofspark plugs 22 by which the compressed charge is ignited.

The outer ends of the cylinders 19 are closed by detachable caps orheads 23, and the inner terminals thereof are provided with valve seats241: for receiving the valves 25, which latter are normally retained inclosed position by the tension of springs 26 and 27. The outer terminalof each valve stem 28 is threaded in a reciprocating piston 29, and thespace 30 between the valve 25 and the piston 29 constitutes thecombustion chamber in which the explosion of the combustible mixtureoccurs. The outer terminal of the piston is rigidly connected normallyretained in depressed position by the tension of a spring 36 coiledabout a depending stem 37 carried thereby. The latch plate is providedwith friction reducing rollers 38 which bear against the guide plate 35and the head 23, and. tl e lower terminal of the stem is bifurcated toreceive a rolls 39, which bears upon a earn el-(l secured to a cam shaftll underneath each cylinder 19. The object of the cams 49 is to elevatethe latch plate against the tension oi the springs 36 to release thepistons 29 to permit the latter to move "orwardly to close the valve 25under the influence of the several springs 26 and 27.

The piston 29 is provided. intermediate its ends with acircuintorrential groove i2, which, when the valve is in closed psition, registers with the inlet port 41:3 in the lower part of eachcylinder ill whereby the explosive mixture is conducted from the cl? bow4:4 to the groove Pt snring: actuated check valve l5 is arranged in theinner terminal of the elbow ll to prevent back prev, sure in the latterand. the groove 4:2 com-- Inunicates by plurality of angular inlet ports46 formed in the piston with the cornbustion chamber 30. hen. the valve253 is in closed position, as illustrated in Fig. 2 the inner terminalsof the inlet ports 46 coin- Inunicate with the chamber 30, but when thepiston is moved outwardly as when an enplosion occurs in the chamber 30,the inner terminals of the norts 46 are covered by the wall of thecylinder 19, thus closing); the ports and preventing the explosion fromleaking back into the inlet port 43. The piston 29, as will beunderstood, is of considerably greater diameter than the valve 25, sothat the effect of th explosion in the combustion chan'iber 30 is tomove the pis ton 29 outwardly and thus open the valve 25, permitting;the expanded gases to discharge through the inlet port 20 and afrainstthe blades 21 of" the rotor associz" l with the cylinder in which theexplosion occurs.

l Vhen the piston 29 is forced out *ardly by the impact of the explosionin the (llflfih ber 2-30 it is locked in retracted position tor a briefperiod by the latch plate 3 1i, which drops into the recess in the rod31 and prevents the return n'iovenicnt of the piston and valve under theinthiencc ot the springs 26 and 27. The latch plate is released orelevated to permit the piston and valve to assume their former positionby the cam 40.

A cam shaft 41 is supported in hearings 41 secured to the rotor housing7. @nc end of the shaft 41 is rotatably supported in the governorhousing" 48, which is arranged laterally of the gear housing 8 and formsan inclosure for the bevel gear wheels 49., conmeeting the cam shaft Hwith the inclined drive shaft 50. The shaft 50 projects through the sidewall of the housing 8.

As indicated in Fig. l the reduced terminal 51 of the rotor shaft 9 tuninates adjacent the lower end of the shaft 50 and is mounted ii.bearing 51 carried by the support 15. The reduced terminal of the rotorshaft and the inclined shaft 50 are connected by bevel gear wheels 52,whereby the rotary movement of the rotor shaft is transmitted to theinclined shaft 50 to operate the cam shaft 41 during" o eration Eachgroove 17 in the rotor housing is provided with an outlet port 53,v-rhich is connected with the exhaust pipe 5 1- extending alongside oi?the h-znisin r r l and e):- tending to the inlet port ot the governorhousing 418. The gnivernor housing); 48 is provided. at the end oppisite the inlet port with an outlet port 36, through which the exhaustproducts of combuz-ition troin the several rotors is discharged A Finalexhaust pipe :36 is connected to the port 36. Within the housing 4.8 abladed wheel 57 is slidably and noirrotatably mounted upon the in- \dshaft 50 and is normally retained in inwardly extended position tovmrdthe driven shaift 13 by the tension of a s nking 58, which is confinedbetween the rec ssed hub 59 ot the bladed wheel and. the bearing (30provided in the housing" 48 for the shaft 530. The hub of the bladedwheel is provided with a tubular extension 61, having a flanged upperterminal providing a groove 62.

A double type oi. throttle valve 63 is arran god beneath the governorhousing 48 and includes an outer shell or housing 64; and a core 65having a port 66 therethrough and iner and outer valves (37 and 68respectively. The inner valve 67 is provided with a stem 69 carrying an70, whereby the valve may be conveniently adjusted by hanch and the twovalves are separated by an an nula-r partition 71. The outer valve (38is provided with a hollow stem 72, carrying an arm 73 connected with thetubular e1; tension 32 ot the governor for automatirall y controllingthe passage of the explosive mi:-;- ture to the cyl inders o l theengine; the valve (33 is located in the pipe 75 at a point adjacent theend of the pipe that connects with the reservoir, that will behereinafter more fully described. From one side ot the valve casing 64kthe explosive mixtiu'e is conducted to the several elbows l4 of thecylinders 15) by the inlet pipe The arm 73 is connected to the throttle(32 ot the governor through the medium of a link 73 and a bell crank 74.

The top part of the gear housing 8 at the end opposite the rotor housing7 is provided with a vertically disposed compression cylinder 76, inwhich a piston 77 is reciprocably mounted and is provided with a conneting rod '78, An eccentric strap :79 is connected with the lowerterminal of the rod 78 which embraces'an eccentric 8O onithe drivenshaft 13, whe'reby a reciprocating motion is imparted to the piston 7 7during rotation of the drive shaft 13. The head of the cylinder 7 6 isprovided with a valved inlet port 81 which is connected with a fuelsupply pipe 81 by which gaseous fuel is conducted to the cylinder 76from a carbureter 82". The upper part of the cylinder 76 is connectedwith a tank or reservoir 82 by a pipe 83, and the reservoir 82 isdesigned to contain an adequatesupply of gaseous fuel under pressure. Acheck valve 84 is arranged in the pipe connection 83 between thereservoir 82 and the cylinder 76 to prevent the compressed fuel fromlinding its way back into the head of the cylinder 76. A relief pipe 85connects the lower portion of the reservoir82 with the pipe 83 andpressure operated valves 86 are arranged in the pipe 85, which areadapted to be opened when the pressure of the gaseous fuel in the tank82 reaches a predetermined value so as to cause the fuel to circulateback and forth between the compressor cylinder and reservoir duringreciprocation of the piston 77. The fuel supply pipe 75 for the severalcylinders 19 is connected with the reservoir 82 and is connected with aT shaped pipe 88 arranged within the reservoir. An angular nozzle 89 isarranged in the vertical portion of the T pipe 88, and the discharge endthereof is directed, toward the supply pipe 7 5. The lower terminal ofthe nozzle 89 communicates by a restricted opening with the lowerportion of the reservoir 82, whereby any volatile fuel which condenseswithin the reservoir is conducted to the nozzle 89 which sprays it intothe pipe 75 in the form of vapor.

In operation, the gaseous fuel is conducted from the reservoir 82 to thepipe 75 through the throttle valve 63, again entering the'pipe 75,elbows 4A, grooves 4-2 and inlet passages or ports 46 to the combustionchambers in the cylinders 19. The compression of the compresser cylinderforces the fuel through the reservoir 82 to the port 46. The charge inthe combustion chamber of each cylinder is ignited by the spark producedby the spark plug and the timing mechanism (not shown) for the ignitionsystem is preferably so regulated as to cause the combustible mixture inthe chambers 30 of the several cylinders to be successively ignited atpredetermined periods. The impact of the explosion against the inner endof thepiston 29 effects an outward movement of the latter which opensthe valve 29, permitting the expanding gases to discharge through theinlet port 25 and against the blades 21 of the rotor 18, thus rotatingthe latter. The valve 25 is locked in open position so as to obtain themaximum effect of the expanding gases upon the rotor by the latch plate34, which is moved downwardly by the tension of the spring 36 when thepiston 29 is moved outwardly. The piston and valve are subsequentlyreleased by the cam 40 of the cam shaft 41, which engages the roller 39of the latch plate, thus elevating the latter and disengaging it fromthe recess in the piston-carried rod '31. During the operation of theengine the piston 77 is constantly reciprocated in the cylinder 76 andmaintains the gaseous fuel in the tank or reservoir 82 at apredetermined pressure. The bladed wheel 57 operating inthe housing 48creates a vacuum in the exhaust pipe 54, eliminating back pressure ofthe exhaust products of combustion in the rotor housing 7 and thoroughlyscavenging the exhaust products of combustion. When the engine exceeds apredetermined speed, the atmospheric pressure upon the blades of thewheel 57 forces the latter outwardly against the tension of the spring58, thus shifting the lever 1 and actuating the arm 73 of the valve 68to temporarily out off the supply of fuel to the several cylinders 19,or until the engine is again running at the proper speed.

What I claim is:

1. In an explosive engine, a housing, a rotor mounted in the housing, acylinder having an internal combustion chamber communicating at one endwith the housing, said cylinder having an inlet port therein, a portedpiston arranged in the cylinder normally connecting the inlet port withthe combustion chamber, and adapted to be ac tuated by the explosionoccurring in the combustion chamber to close communication between thecombustion chamber and the inlet ort.

p 2. In a rotary engine, a rotor housing, a rotor journaled in thehousing, said housing having inlet and exhaust ports therein, acombustion chamber communicating with the inlet port, an exhaust pipeconnected with the exhaust port, a bladed wheel connected with the rotorfor creating a vacuum in the exhaust pipe, and means controlled by thebladed wheel for controlling the admission of gaseous fuel to the inletports. a

3. In a rotary engine, a rotor housing, a rotor journaled in saidhousing, said housing having inlet and exhaust ports therein, acombustion chamber communicating with the inlet port, a fuel supply pipeconnected with the combustion chamber, means for controlling theadmission of gaseous fuel to the combustion chamber, a throttle valveconnected with the supply pipe, an exhaust pipe connected with theexhaust port, a bladed wheel operatively connected with the rotor forcreating a vacuum in the exhaust pipe, and means connecting the bladedwheel with the throttle valve for controlling the latter.

4L. In an explosion engine, a housing; a rotor arranged within thehousing; a cylinder having an internal combustion chamber therein; saidhousing having a passage extending from the cylinder to the rotor; saidcylinder having an inlet port therein; a piston arranged within thecylinder and adapted for a reciprocatory movement therein, said pistonhaving a fuel supply channel extending to the combustion chamher andadapted to communicate with the inlet port of the cylinder; and a valveconnected with the piston and adapted to control the communicationbetween the explosion chamber and the rotor.

5. In a rotary engine, a rotor housing,

a gear housing, said rotor housing having inlet and outlet ports, arotor journaled in the rotor housing, a governor housing mounted on theside of the gear housing, and an exhaust pipe connecting the exhaustport in the rotor housing with the governor housing, a bladed Wheelupwardly connected with the rotor for creating vacuum in the exhaustpipe, said bladed wheel located within the governor housing, and meansassociated with the bladed wheel to regulate the speed of the engine.

In testimony whereof I aflix my signature in presence of two witnesses.

ALBERT UNDERDAHL.

lVitnesses:

JOHN J MURPHY, C. J. MINOR.

